(a) Technical Field of the Invention
This invention generally relates to plant supporting structures, particularly directed to vine-type plants. In vine-type plants, such as tomatoes and grapes, the fruits are typically heavier than the plant itself, thus making the entire plant unsteady. These plants therefore require some physical structure that will support the fruits, keep them spaced apart so as to provide sufficient room to grow, allow sunlight to reach its different parts, provide adequate air flow, and also be able to hold steady during strong winds and rain. Another important consideration is to keep the plants and fruits off the ground so as to keep them free from bugs and insects, and to keep them clean.
In the past, stakes have been used, to which the plant has been tied for support. In such cases, the stakes are typically unsteady and provide limited support. As a result, the plants' stems get broken; the fruits clump together and eventually may sag to the ground. Many plant supporting structures appear in the prior art that attempt to address one or more of these problems.
(b) Description of the Relevant Art
A considerable number of patents relate generally to tomato cage structures. These prior art structures take a variety of general shapes and forms.
In U.S. Pat. No. 5,179,799, Hillestad discloses a tomato plant support system that consists primarily of a series of horizontal rings connected by vertical risers. In that sense, it is similar to the current invention. However, a key component of the Hillestad system is the fact that each of the horizontal rings includes the formation of double open ended loops forming seats along the ring. Specifically, three seats are disposed around the perimeter of the ring. As with the present invention, the rings are of varying diameter. The open ended loops form seats that are used to connect the members together for assembly.
Another tomato cage is found in U.S. Pat. No. 6,874,276 B2 by Morrison. The Morrison tomato cage also consists of a series of horizontally displaced support rings and vertical risers connecting them. The concentric rings are arranged such that the rings with the smallest diameters are located at the bottom. However, the support legs terminate in a specific handle. In this structure, the handle is integral with the legs of the device so that when the Morrison device is forced into the ground, the force does not affect the concentric rings. Another published patent application by Morrison US 2004/0237393 A1, from Dec. 2, 2004, is directed to the same invention as the Morrison patent.
U.S. Pat. No. 4,372,351 by Myers is a method patent directed to a method of producing a particular style of wire basket that could be used to support a plant. The basket could also be used for other purposes as well. The method claims require the production of a plurality of wire loops that are then connected by concentric horizontally disposed rings, as best illustrated in FIG. 1 of the Myers' published patent.
U.S. Pat. No. 5,174,060 by Glamos is a variety of plant stand that is generally in the shape of a cone. The arrangement requires a primary helical coil support member, identified with the number 20 in FIGS. 1 and 2 of the published patent.
Another tomato cage structure is found in U.S. Pat. No. 4,858,380 by Gayle. However, the Gayle structure requires two separate independent enclosure structures. The larger of the two structures is a barrel-shaped cage of a specified diameter that sits on top of a smaller diameter support structure. The Gayle device requires a two piece construction.
Many of the prior art devices found are very old, as set forth in long expired patents. For example, U.S. Pat. No. 2,181,016 by W. F. Gross is a plant protection device essentially taking the form of a rounded glass cage. The Gross structure includes rounded glass side panels, which makes it unsuitable for the uses that have been established for this invention. Moreover, glass is heavy, expensive and fragile.
Many of the prior devices found consist of square or rectangular support structures and many other patents describe support stands that are designed to be quickly assembled and disassembled. For example, please note U.S. Pat. No. 3,113,400 by Emond, U.S. Pat. No. 4,073,091 by Vogel, U.S. Pat. No. 4,285,163 by Booker Jr., and U.S. Pat. No. 4,667,438 by Corell.
A review of the prior art reveals that an effective and stable plant supporting structure needs to provide a number of key functional improvements. Not only must the structure serve to keep the plant and its fruits off the ground, the structure must also be sturdy and provide effective support so that the plant may be protected even under adverse weather conditions, without the need to apply strings or rope directly to tie the plant, and generally lower maintenance as the plant grows and extends. The design of the structure should prevent from running the cultivator too close to plant roots. This structure should also provide excellent air circulation for the plant and improve the reception of sunlight. It should prevent crimped or partially broken plant stems that can prohibit natural plant fluid transfer, thereby causing disease and decay. Additionally, the structure should support multiple plants, keeping both the plants and the fruits off the ground. These and other key improvements are embodied in the present invention.